Multiple switchboard for telephone-exchanges



(No Model.)

W. S. NASH. MULTIPLE SWSEOEEOAED FOR TELEPHONE EXCHANGES. No. 591,192.Patentedflot 5,1897.

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WALTER S. NASH, OE KNOXVILLE, TENNESSEE.

SPECIFICATION forming part of Letters Patent No. 591,192, dated October5, 1897.

Application filed m 20, 1897.

To alZ whom, it may concern:

Be it known that LWALTER S. NASH, a citizen of the United States,residing at Knox ville, in the county of Knox and State of Ten nessee,have invented certain new and useful Improvements in MultipleSwitchboards for Telephone-Exchanges; and I do declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, and to theletters of reference marked thereon, which form a part of thisspecification.

My invention relates to improvements in multiple switchboards fortelephone exchanges.

It consists in the combination of a generator of the well-known typeproperly grounded and adapted, when energized, to transmit vibratorycurrents through test-circuits comprising a series of contact-plates inelectrical connection with said generator and with each other, improvedspring-jack switches in electrical connection with correspondinglynumbered and constructed springjacks onthe other multiple boards of theexchange, each having two contact-arms extending from the front and backof the spring jack frame and parallel to, but not connected with, eachother, the arm thereof projecting to the front being in electricalconnection with a subscribers line and the one projecting to the rearbeing in similar connection with the eye or metallic rim of thespring-jack switch and adapted, when depressed by the insertion of aswitch-plug, to electrically engage a con-' tact-plate in circuit withsaid generator, and test-plugs insulated along their cylindricalperipheries, each provided with a conducting-core exposed at one end andelectrically connected at the other end with a pivoted hand-switchadapted, when drawn backward, to close the test-circuit through theoperators head-phone and when pushed forward to break such circuit, andby tapping directly on another connection with said generator to ring upboth subscribers, a more detailed description of the construction andoperation of my device being as hereinafter set forth.

In the drawings forming a part of this specification, Figure 1 is a sideelevation of Serial No- 637,384. on, inadel.)

M M are sections of multiple switchboards provided with thecontact-plates P P, insulated from, but secured to, said switchboards MM in any well-known manner.

J J are spring-jacks connected with the spring-jackof the otherswitchboard through the wire j, said spring-jacks being connected to thetest-thimbles G O. Line-switches S S are provided and are connected inthe usual manner with the subscribers wires L L.

The switch-plugs E E are composed of cylinders of non conductingmaterial N N, through each of which projects a metallic core,terminating at one end in the point e e and at the other in a flexibleinsulated conducting-cord 79 b and are in electrical connection with thehand-switch H, which is pivoted at h to a non-conducting surface and isprovided with the arms 72/ andh I O is the operators head-phone inelectrica connection with the projections 0' on the contact-arm 0 andproperly grounded.

I G is the generator, grounded in the'usual manner, which is providedwith the feed-Wire g therefrom to the contact-plates P P, and alsoprovidedwith the annunciator connection 9, adapted,when the arm 72/ ofthe ban dlever H is brought into contact with the projection c" on thecontact-arm r, to establish an annunciating-circuit from generator Galong the annunciator connection g", the contactarm 9", the projection ron the contact-arm r, the horizontal arm h of the hand-switch H to h,thence along the conducting-cordb to and through the switch-plug E,line-switch S, line L to the subscribers telephone, ringing his bell,and simultaneously closes the annuncia tor-circuit through the othersubscribers telephone through the drop connection d, which is inelectrical engagement with the switchlever H at h, the contact-arm a,the projection aon the contact-arm a, the spring-switch a the switchconnection a the plug-cord b and thence through the switch-pluginelectrical connection with the subscribers lineswitch and line in theusual manner.

The operation of my device is as follows: When the switch-plug E isinserted through the test-thimble O of the spring-jack J, the

point e of the switch-plug E electrically engages the spring S, therebyestablishing the line-circuit L, and at the same time the insulatedcylinder N depresses the test-switch s, so that the projection 19thereon is brought into electrical connection with the contact-plate P,when the test connection is completed through the generator G, thefeed-wire g, the contactplate P, the test-thimble O, the wire j inelectrical connection with the spring-jacks J J and the test-thimble Oof the spring-jack J, so that if the point e of the switch-plug E isbrought into contact with the test-thimble O of the spring-jack switch Jthe test-circuit is established thence through the metallic core of theswitch-plug E, the conducting cord 1), the horizontal arm h of thehandswitch H, the projection 0 of the contact-arm 0 to the operatorshead-phone O, in which the alternation of the generator-current i-n- Itis obvious that if the point of the switch-plug dicates that the linethus tested is in use.

be applied to the test-thimble of a springtrical connection with thespring-jacks to be tested are not in usethe test-circuit is notestablished, and the operator knows by the absence of vibrations in thehead-phone that the tested line is not busy. If the linetested is notbusy, the operator makes the connection with the desired line in theusual manner, and by reversing the switch-lever H and bringing the arm1L thereof into electrical engagement with the point r on thecontact-arm 1 establishes the calling-circuit through the connectedlines, as hereinbefore set forth.

In my device it is apparent that wires in electrical connection with thewire 9 may be substituted for the contact-plates P P, and that theswitch (described as switch-lever H) may be adapted to be operated by apivoted pedal or equivalent mechanism.

By the foregoing it will be noted that 'my' switching-test apparatus issimple and effectwe, dispensing, as it does, with intricate connectionsand at the same time affording a more distinct and unmistakable testthan by other devices of this character heretofore operated, and at thesame time affords a satisfactory and convenient apparatus for making andbreaking the calling-circuit.

Having described my invention and its operation, what I claim, anddesire to secure by Letters Patent of the United States, is

In multiple switchboards for telephone-exchanges, the combination of thesubscribers telephone in electrical connection with correspondingline-switches on several multiple boards of the exchange, each attachedin a suitable manner to the frame of a corresponding spring-jack, atest-thimble to each of the spring-jacks, spring-switches, one end ofeach being in electrical engagement with the testthimble of acorresponding spring-jack, and adapted to be operated by the insertionof a suitable switch-plug through the thimble of the spring-jack, meansfor electrically connecting the thimbles of corresponding springjacks onthe several multiple boards of the exchange, contact-points inelectrical connection with a suitable generator and adapted toelectrically engage said spring-switches when same are depressed,switch-plugs insulated save at their extremities one of said switchplugsbeing inserted through the test-thimble of a spring-jack in electricalconnection with a corresponding springswitch, from which it isinsulated, into electrical engagement with one of said contact-points, asimilar switch-plug on a different multiple board of the exchange, aswitch-lever in electrical connection therewith, an arm on saidswitchlever, adapted when the switch-lever is operated in one directionto engage a contactpoint in electrical engagement with the op-.

as described.

In testimony whereof I affix my signature in presence of two witnesses.

WALTER S. NASH.

WVitnesses:

W. A. GAGE, W. O. LAwsoN.

